1. Field of the Invention
The present invention relates generally to a communication system. More particularly, the present invention relates to an apparatus and method for transmitting and receiving MAP information in a communication system.
2. Description of the Related Art
In a communication system, a transmitter and a receiver, for example a Base Station (BS) and a Mobile Station (MS), use a frame structure for both the transmission and the reception of data.
In a conventional communication system, the transmission of data using a frame structure includes the transmission of MAP information. MAP information, in data transmitted by the BS, includes data extraction information, such as position and size of the data, allocated separately for each mobile station, and a variety of information used for providing service separately to each mobile station. Therefore, each mobile station receiving the MAP can extract its own transmitted data burst in the frame by analyzing the MAP information.
In the conventional communication system, when the BS transmits the MAP information, the BS applies therein the same coding scheme and the same modulation scheme for all MSs to which resources are allocated. In this case, the coding scheme and the modulation scheme are determined and applied by the BS such that even an MS located in a cell boundary can receive the MAP information without error. Therefore, to ensure reception by even an MS in a cell boundary, the BS transmits the MAP information using a low modulation order, a low coding rate, repetition, etc. For example, the BS may use Quadrature Phase Shift Keying (QPSK) 1/2 and set the number of repetitions to 6 (repetition=6) to repeatedly transmit the MAP up to six times to ensure reception by an MS in a boundary area.
described above, the MAP information should be determined such that even an MS located in a cell boundary can receive it without error. However, the MAP information transmitted by the BS, which is a kind of control information for data restoration, is a source of overhead in the entire system. Since the MAP information transmitted to an MS located in a non-cell boundary is transmitted taking into account an MS located in a cell boundary, more than necessary coding schemes and modulation schemes are applied, which unnecessarily increases system overhead.